I’m afraid there’s not enough information here yet for helpers to understand what’s going wrong (in general, it’s a good idea to at least try to fill out the “System Information” section in the above template before posting your problem). Here’s what I think you can do to make it easier for others to help:
Run the following lines in the RStudio Console pane, and paste all of the output here:
sessionInfo()
rstudio::versionInfo()
(When you paste in the output, please don’t forget to format it properly by selecting it and clicking the little </> button at the top of the posting box). This will show us all the relevant system information.
Can you describe the symptoms of your problem in more detail? When you say you are not seeing packages anymore, do you mean in the Packages pane, or somewhere else? Do you mean only certain packages are not visible where you expect, or all packages?